Electrical swivel disconnector



Nov. 4, 1947. M, BERGAN 2,430,270

ELECTRICAU SWIVEL DISCONNECTOR Filed March 21, 1945 Mai-fin 1372525? dim/QM ATTORNEY Patented Nov. 4, 1947 ELECTRICAL SWIVEL DESC'ONNECTOR Martin D. B'ergan, Westfield, N. l, assignor to The Thomas & Betts (10., Elizabeth, N.. J., a corporation of New Jersey Application March 21, 1945; Serial No. 583,937

2 Claims. 1

This invention relates to a new and useful swivel electrical disconnectc-r, the present application being a continuation-in-part of my former application entitled Electrical couplin disconnector, and filed January 15, 1943, under Serial Number 472,436.

A primary purpose of the invention is to provide a connector having contact parts which swivel in relation to each other and which have a dual function, wherein a firm mechanical disengageable grip and a low resistance electrical connection are independently established between the movable or oscillating parts.

Accordingly, the two independent connecting means perform their separate functions in a manner which provides a new mode of'operation, affording maximum holding tension or pull-out value between members of given size, and likewise maximum current transmitting value therebetween.

The accompanying drawings illustrate the invention, present an example of its structural form,

and suggest other embodiments which come within the principle of the invention.

The example of construction shown herein includes a disengageable contact ball and resilient clasp in the form of a wire terminal which provide for a dual mechanical and electrical connection, the ball or spherical member aifording a free swiveling action between the two metallic parts constitutin the connector.

The description and drawings herein explain the principle of the invention and present the best mode now contemplated in applying such principle, so as to distinguish the invention from others; and there is particularly pointed out and claimed, in so far as is known by comparison with the art, the part, improvement or combination, which constitutes the invention or discovery,

Fig. 1 shows the electrical connector in disengaged position. The connector terminal clasp is shown just above the contact ball, and in readiness to engage it.

Fig. 2 shows the connector parts plugged together, the diverging dotted lines indicating the range of angular or swiveling movement ofv the connector clasp in relation to the contact ball. In this view, the position of the connector clasp is shown at right angles to that of Fig. 1.

Fig. 3 is a sectional view taken on the line 33; while Fig. l is a section developed along the line 4-4.

Fig. 5 is a. diagrammatic view of the sprin gripping arms, forming a portion of the connector clasp or terminal before and after making disengageable connection. with the ball contact.

Fig. 6v is similar in purpose to the previous view, but illustrates the position of the electrical con tact legs, another portion of. the connector clasp, before and after making disengageable connection with the ball contact.

Referring further to. the drawings, a ball or spherical contact It has a shank ll carrying a wrench or toad-receiving portion in the form of a nut I2 by which to screw a threaded shank or stud l3 into a panel P of an instrument board or other device ormachine part with which the connector may be, used. Anysuitable instrument wiring. connection (not shown) may be electrically connected with the. threaded stud It. The panel P merely represents one commercial application, while the threaded stud r p sents one of themany different types of mounting means, and also a wire conductor receiving means, for the disconnect contact ball or spherical portion ll! of the connector.

A. connector clasp or terminal, including a head or base It, may be approximate in size, spread, or area to that of the; diameter of the contact ball it. A. wir conductor receiving means, in the form of a sleeve i5, isv carried on the back side of the head. l4 forming the base portion of the connector clasp, the reference number is designating the clasp as a whole. An electrical wire W (usually a flexible cable strand) is inserted into the sleeve i5 and bonded thereto in any approved manner. Thus current is transmitted from the wire W to the connector clasp I l which is adapted for manual clasping connect and disconnect operation (and a swiveling action if desired) in relation to the contact ball H).

A set or plurality of resilient mechanical grippings arms is are shown as being formed integrally with the perimeter of the clasping head l4 (as at right angles thereto) and extended from the front side thereof toward the contact ball is. The several mechanical gripping arms it are equidistantly spaced on the head M of the clasping terminal. The edges of the arms it are seen in Fig. 2, whereas in Fig; 1 their outer surfaces are seen, due to the fact that the two views show the connector clasp from two positions, one at ninety degrees from the other.

Each resilient arm l5 has a ball-pocketing finger is. formed on its outer free end which flexes with the arm. And each finger I 8 is curvilinearly or angularly formed to bow outwardly with an internal shape to fit the surface of the ball contact it. Thus the outward bows provide inwardly dished surfaces on the fingers l8, facing the axis of the clasp l4, and adapted to engage the ball ID for establishing a disconnectable gripping hold thereupon.

For simplicity in illustrating the principle of the invention, Fig. 2 suggests that two mechanical ameter of the ball Hi. In other words, the resilient arms [6 are set to hold the fingers [8 on a predetermined diameter which will grip and hold the ball with an appropriate or given force to resist separation of the clasp M from the ball [0. Accordingly, the resilient arms l6 and their ball-gripping fingers 18 may be produced for manual connect and disconnect operation with an approximate given force, andthus have a separating or disconnect pull-out value in pounds of force applied thereto which is suited to the particular use for which the connector may be produced.

The dotted line position (Fig. 5) of the ballgripping fingers l8 illustrate the inwardly sprung pre-set position thereof before being plugged onto the ball 1!). The resilient gripping arms 16 are cammed apart when manually forced onto the ball, and then snap closed, as shown in solid lines. Thus the arms expand in camming over the high point (maximum diameter) of the ball 16, and then contract as the fingers I8 come to rest. This arrangement establishes a mechanically swiveled connection between the ball ill and clasp 14.

Electrical contact legs or springs I9 are also integrally formed on the front side and at the perimeter of the clasp head l4, being equidistantly spaced between the ball-gripping arms l5, and equal in number to said arms for more satisfactory operation. These electrical contacts l9 are concentric with the axis of the clasp [4, as indeed also is true of the ball-gripping spring means [6, 18. The two groups of resilient members (arms l6 and contacts I9) in effect constitute an electrical plug-on receptacle for the ball H! where the latter is mounted in stationary position as shown in the drawings, although in other installations the arrangement may be reversed and the clasp M may be mounted stationary so that it acts as a plug-in receptacle for receiving the manually operated disconnect ball l0.

The group of contacts [9, two or more thereof for satisfactory results, may be formed straight and extend from the head of the clasp [4 alongside of and between the specially shaped arms l6, l8. Thus the simple straight formation of the contacts i9 is in contrast with the shape of the mechanical gripping fingered arms, the reason for which will be explained. In this connection, note Fig. 6 which is a diagrammatic view presented in aid of explaining the functional distinction between the two sets of spring members l6 and I8 adapted for swiveling disconnect engagement with the contact ball [0.

The straight spring contact legs 19 (observing Figs. 1 and 6) are pro-set on a diameter somewhat smaller than that of the ball ID, that is, the distance across the circle which defines the position of the outer free ends is smaller than the ball when not engaging it. The dotted lines (Fig. 6) show the pre-set or inwardly sprung contacts l9 which converge toward their outer free ends before (Fig. 1) plugging the connector clasp M onto the ball If). But when the clasp and ball are fully engaged, the severalcontacts l9 line up in parallel relation.

When the outer ends of the electrical contacts 19 first engage the surface of the ball Ill, the spherical surface of the latter acts to cam open and spread said contacts; and as the clasp I4 is pushed further onto the ball, the contacts i9 slide onto the maximum diameter of the ball and remain there, doing so without drop in the maximum spring-loaded tension or pressure imparted to the contacts by the maximum diameter of the ball. In other words, the group of contact legs E9 (in contrast to the action of the fingered gripping arms l6, l8) expand to a maximum to embrace the ball Ill, and thereafter never contract or yield.

The latter characteristic means that the very maximum pressure engagement, of which a given size contact is is capable, is applied and maintained against the ball [0, thereby providing maximum current transmissison through a swivel joint of low current resistance. Accordingly, the electrical contact legs l9 are designed and provided only for current transmission while, on the other hand, the fingered gripping arms l5, 18 are utilized for establishing the mechanical connection between the two parts.

Since independent parts or portions are provided for distinct mechanical and electrical connecting functions, it follows that modifying the function of one does not impair the function of the other. Consequently, in manufacturing operations, the mechanical connecting means (fingered arms l6, 18) can be formed with such appropriate tension and pull-out value, to release from the ball 10 by a heavy pull or a light pull, as required for a particular electrical installation without interference from or limitation by the electrical contact legs 19. Indeed, the constant pressure contact legs is make the same lowresistance electrical connection through a swivel joint of low pull-out value as one of high pull-out value.

It is noted that the mechanical gripping arms l6 and the contact legs !9 are alternately arranged, or staggered, one between the other. Also the outer flexible ends of the group of resilient members l6 and i9 converge to define a circle somewhat smaller than the size f the head portion [4 of the clasp. And by way of further comparison, the circular area bounded by the outer tip ends of the concentrically disposed members l6 and i9 is smaller than the diameter of the ball I0.

The wire W and disconnector clasp l4 readily swivel or oscillate upon the ball ll], if need be, as indicated by the angular spread or divergence of the dotted lines (wire W) in Fig. 2. Thus the connector finds utility in installations where it is desirable to afford play and movement of a conductor cable W leading off from its service connection NJ to some other apparatus, especially where a quick disengageable electrical connection i required.

It is noteworthy that the dual-function clasping terminal [4 lends itself to adjustment by a mechanic on the job. If need arises, he may readily increase or decrease the tension of the clasp on the contact ball it by carefully using his pliers to slightly open or close the mechanical gripping arms I 6 without disturbing their resilient pre-set strength designed and engineered by the manufacturer into the electrical contacts 19. Thus the connector remains constant in respect to its electrical connection, whether or not swiveled to various positions, but may be increased or decreased in respect to its pull-out value.

Additional advantages and commercial applications of use are also found by adapting the contact ball portion ill to supporting or mounting means, and wire connectin means, other than the simple stud type H, [2 here shown merely for convenience in explaining the principles involved in connection with a connector which may comprise two simple parts. Indeed, the terminal contact ball I0, with any suitable form of wire connection, other than as indicated at I3, may be attached to a wire conductor for plug-in connection with the terminal clasp l4 and not require support in a panel P or other like stationary member.

This invention is presented to fill the need for a useful swivel electrical disconnector. Various modifications in construction, mode of operation, use and method, may and often do occur to others, especially so after they have benefited from the teachings of an invention. Accordingly, this disclosure is exemplary of the principles and equivalents without being limited to the present showing of the invention.

What is claimed is:

1. An electrical wire connector in the form of a clasping terminal, comprising a, head portion, from which extend several resilient members disposed concentrically about a common axis, and the outer free ends of which define a circle smaller in area than the size of the head portion, certain of the resilient members being formed straight and adapted to expand and remain expanded to establish and maintain constant electrical contact pressure on a ball with which the clasping terminal is adapted to cooperate, and other resilient members being bowed outwardly to form inside pocketing surfaces adapted to expand and thereafter'contract to clasp the ball and establish a secure mechanical grip thereon, the straight and the bowed resilient members being disposed alternately one to the other around said common axis.

2. An electrical disconnector comprising coopcrating members in the form of a contact ball and connector clasp, with means for connecting an electrical conductor to each member; wherein the clasp includes a head portion, from which extend resilient contact legs disposed on a common axis, the outer ends of the legs being free to flex, said legs converging toward their free ends and defining a circle which is smaller than the diameter of the ball, the legs resiliently engaging the ball and being expanded and spring tensioned and restrained against contraction by said ball, the reaction of such tension providing an electrical contact of maximum pressure between the ball at its maximum diameter and the converging legs j and resilient gripping arms also extending from the head portion and disposed on said axis and also converging as well as defining a circle which is smaller than the diameter of the ball, the outer free ends of the gripping arms being free to flex and bowed to form ball-pocketing fingers, the fingers resiliently engaging the ball and being expanded and spring tensioned thereby, and being disposed on the ball past its maximum diameter, whereupon the resilient gripping arms react and cause the bowed fingers to contract, thus clasping the ball surface at position beyond its maximum diameter.

MARTIN D. BERGAN.

REFERENCES CITED The following references are of record inv the file of this patent:

UNITED STATES PATENTS Number Name Date 826,287 Svenson July 17, 1906 937,052 Cuno Oct. 19, 1909 1,509,224 Berthold Sept. 23, 1924 1,836,293 Strahan Dec. 15, 1931 1,854,489 Sebell Apr 19, 1932 FOREIGN PATENTS Number Country Date 427,367 France Mar. 14, 1911 469,448 Great Britain July 22, 1937 

